1. Field of the Invention
This invention relates to ruminant feedstuffs and feedstuff supplements. More particularly, this invention relates to ruminant feedstuffs and feedstuff supplements containing a particulate proteinaceous feed material which has been rendered relatively stable to solutions having a pH value larger than 5 but unstable in solutions having a pH value smaller than 4 by treatment with an aldehyde or polymer based on vinyl or acrylic monomers. The feedstuff of the present invention is improved in that there is included at least one nonproteinaceous nitrogen compound, especially present in a weight ratio of 0.1 to 10.0, based upon the nitrogen content of the first stomach stabilized particulate proteinaceous feed material.